Circular knitting machines for the production of hosiery with double, outwardly turned-over welts



Jan. 31, 1967 TENCONI 3,301,012

CIRCULAR KNITTING MA NES FOR THE PRODUCTION OF HOSIERY WITH DOUBLE,OUTWARDLY TURNED-OVER WELTS Filed Dec. 24, 1964 6 Sheets-Sheet 1 i s Y x10 N 4 Jan. 31, 1967 R TENCONl 3,301,012

CIRCULAR KNITTING MACHINES FOR THE PRODUCTION OF HO'SIERY WITH DOUBLE,OUTWARDLY TURNED-OVER WELTS Filed Dec. 24, 1964 6 Sheets-$heet 2INVENTOR.

R. TENCONI nFan. 31, 1967 CIRCULAR KNITTING MACHINES FOR THE PRODUCTIONOF HOSIERY WITH DOUBLE, OUTWARDLY TURNED-OVER WELTS Filed Dec. 24, 19646 Sheets-Sheet 5 INVENTOR.

Jan. 31, 1967 R. TENCONI 3,301,012

CIRCULAR KNITTING MACHINES FOR THE PRODUCTION OF HOSIERY WITH DOUBLE,OUTWARDLY TURNED-OVER WELTS Filed Dec. 24, 1964 6 Sheets-Sheet 4 I NVENTOR.

R. TENCONI Jan 31, 1967 CIRCULAR KNITTING MACHINES FOR THE PRODUCTION OFHOSIERY WITH DOUBLE OUTWARDLY TURNED-OVER WELTS Filed D90. 24, 1964 6Sheets-Sheet 5 INVENTOR.

Jan. 31, 1967 R. TENCONI 3,301,012

CIRCULAR KNITTING MACHINES FOR THE PRODUCTION OF HOSIERY WITH DOUBLE,OUTWARDLY TURNED-OVER WELTS Filed Dec. 24, 1964 6 Sheets-Sheet 5 33 23bA \u JIM/1,, 3

INVENTOR.

lie in the additional grooves of the related sinkers.

United States Patent (IHRCULAR KNITTHNG MAQHINES FUR THE H29- DUCTKUN @FHQSIERY WITH DGUBLE, GUT- .WARDLY TURNED-OVER WELTS Riccardo Tenconi,Varese, Italy, assignor to Marcella Sessa, Varese, Italy Filed Dec. 24,W64, Ser. No. 420,955 Claims priority, application Italy, Jan. 3, 1964,179/64 8 Claims. Cl. 664ll) This invention relates to circular knittingmachines for the production of hosiery, such as stockings and socks,with double, outwardly turned-over tops or welts.

Various arrangements have been proposed for eliminating the transferbits, the dial in which they are supported and the respective drivingmeans, which devices have been used in conventional circular knittingmachines for the production of double, inwardly turned-over welts. Inall of these previously proposed arrangements, the regular knittingneedles are used for the production of the double welt and arealternately formed with long and short butts and special sinkers areemployed which have an additional groove below the usual knitting levelor ledge to form a lower ledge. In all of these proposals, the loops ofthe first course, or of a few initial courses, are held so low on theneedle shafts during the formation of the double welt by the additionalgrooves of the sinkers that they cannot be cast off, and these retainedloops are then released, after the welt is completed, to knit thereleased loops together with a further course.

In a known machine of the above type, the thread for the formation ofthe first course of the welt is fed to all needles and, in order toensure that the loops of the initial course on alternate needles are notcast off during the formation of the following courses, these loops areso lowered on the respective needles that they come to In order tooperate in the foregoing manner, a selective control is provided for thesinkers by means of which either alternate sinkers or all sinkers can beactuated, that is, retracted radially .outward. Since circular knittingmachines usually do not have a pattern device which is capable ofeffecting such selection of sinkers, an addi tional control is requiredleading to considerable complication in the construction of the machine,and further there is no assurance that the alternating loops of thefirst course will be held low on the respective needles.

In order to avoid the above disadvantages, another proposal has beenmade, based on the same fundamental principle, and according to whichone or more initial courses of welt are formed on the lower cast-otfledges of the special sinkers while all other courses of the welt areformed on the regular or upper cast-off ledge and joined with the,initial courses formed on the lower castoff ledge of the sinkers by aconnecting course, and, finally, the courses held down by the additionalgrooves of the sinkers are connected with the last course of the weltand the remaining parts of the stocking are subsequently knitted in theusual Way.

In a machine capable of operating in the manner de-- scribedimmediatelyabove, there are provided selectively engageable and disengageableadditional cams. One ad ditional cam is associated with the knitting camportion of the needle cams and the other additional cam is associatedwith the cam portion for effecting the outward movement of the sinkersfor the purposes of increasing the downward movement or withdrawal ofthe needles and the outward movement of the sinkers, respectively, so asto selectively effect the formation of stitches on the lower or on theupper cast-off ledges of the sinkers. Further, the profiled guide-ringfor the needle butts lifts the needles insufiiciently to engage thethread fed by the thread guides, and a lifting cam is provided which canbe engaged or made operative by a suitable control to lift the needlessufficiently for release of their latches and for engagement with thethread fed by the thread guides. This lifting cam is controlled so thatit acts only on the long butt needles during the formation of the firstcourse, at which time the additional cams associated with the knittingcam portion and the sinker cam are also engaged or operative. Thelifting cam also acts only on the long butt needles during the formationof the next course, at which time the additional cam associated with thesinker cam is inoperative. The lifting cam, acts if necessary, on allneedles during the formation of a course following this latter course,while it is again inactive for the short butt needles during theformation of the course following the last mentioned course, after whichit is finally engaged to act on all needles. The additional camassociated with the knitting cam portion is controlled so that it isoperative for all needles during the formation of the initial course orcourses together with the additional cam associated with the sinker cam,so that it remains active for a part of the needles during the formationof at least one course following these initial courses, and so that itis subsequently made inactive for all needles.

In a machine of this type it is also known to use the regularstitch-widening device in order to permit the formation of stitches inthe course in which the additional sinker cam is already inactive andthe needle lifting cam acts only on the long butt needles, that is, inthe course following the connecting course between the coursesrespectively formed on the lower cast-off ledges and the upper cast-offledges of the sinkers. The result achieved by the stitch-widening devicecan be alternatively achieved by leaving the additional cam associatedwith the withdrawing or knitting cam engaged in the respective course.

Even though the last described machine, when operated as above, isreasonably reliable in its production of the double welt, it has beenfound in practical operation that there remains some danger of threadbreakages, due to excessive tensions, particularly at the criticalmoment of the connection of the courses formed on the lower and uppercast-off ledges of the sinkers. Further, difficulties are encountered inthe production of those parts of the stocking, such as the heel and toe,which are knitted with an oscillating movement of the needle cylinder.Such difficulties are due to the presence of the additional camassociated with the withdrawing or knitting cam for the needles.

As is known, during the production of the heel and toe of the stocking,the needles, after having been lowered by the withdrawing or knittingcam, must be raised again practically immediately and may only remain inthe lowered position for a short time. However, if an additional cam isprovided in association with the withdrawposition before they can belifted again.

It is an object of the invention to eliminate the above disadvantages ofthe known arrangements provided in circular knitting machines for theproduction of hosiery with double, outwardly folded over welts, withoutrequiring the use of transfer bits.

A further object is to avoid the danger of thread breakages, and toensure that difiiculties or imperfections will not arise during theknitting of stocking parts other than the double welt by reason of thoseelements provided in the knitting machine for the knitting of the doublewelt.

The solution to this problem in accordance with this invention is basedon the finding that it is not necessary to form the first courses, whichare held down by the lower additional grooves of the sinkers during theproduction of the welt, on additional lower cast-off ledges of thesinkers, but that it is only necessary that these initial courses be atthe level of the lower sinker grooves at the moment when the knittingmachine starts to form the connecting course between the initial coursesand the following courses. Thus, according to the invention, thestitches are always formed on the same cast-off ledges of the sinkersbelow which the latter have additional or lower grooves, and at leasttwo initial courses are formed at first and then lowered to the level ofthe additional grooves of the sinkers, whereupon a connecting course isformed between the lowered initial courses and the following courses.

The above operations are practically performed by a circular knittingmachine which is provided with needles alternately having long and shortbutts, special sinkers with additional bottom grooves below the usualcast-off ledges, a lifting cam for the needles which can be selectivelycontrolled so that it only lifts the long butt needles or all needles sofar that the needle latches are released and the needles can engage thenew thread fed by the thread guides, as well as additional cams in theneedle and sinker cam assemblies which can be activated by suitablecontrols in order to respectively extend the downward movement of theneedles and the radially outward movement of the sinkers as comparedwith the usual downward movement of the needles and outward movement ofthe sinkers.

According to the invention, the additional cam in the needle c-amassembly is displaced, in the direction of the normal needle cylinderrotation, from the lowest point of the withdrawing or knitting cam, andthe profile or guide ring for the needle butts is provided with a stepbetween the lowest point of the withdrawing cam and the additional cam,so that the needles lowered by the withdrawing cam can be liftedimmediately by such step.

The additional cam in the sinker cam assembly is likewise displaced, inthe direction of the normal needle cylinder rotation, from the regularsinker cam portion effecting the outward movement of the sinkers, andthis additional cam is controlled so that it acts on all sinkers duringthe formation of a single course which follows at least one initialcourse and precedes the connecting course, at which time the additionalcam associated with the withdrawing or knitting cam acts on the longbutt needles.

In a particular embodiment of the invention, the additional cam in theneedle cam assembly not only functions to lower the initial coursesbefore the connecting course is formed, but also serves to adjust thewidth of the stitches, to which end this additional cam is verticallydisplaceable by means of a separate control. In this case, theadditional cam of the needle cam assembly replaces the regularstitch-widening device, which consists, as is known, of means forlifting and lowering the entire needle cylinder.

The above, and other objects, features and advantages of the invention,will be apparent in the following detailed description of illustrativeembodiments thereof which is to be read in connection with theaccompanying drawings, wherein:

FIG. 1 is a schematic, vertical sectional view of a circular knittingmachine of a type that may embody this invention;

FIG. 2 is a developed view of the needle cam assembly of a machineembodying this invention;

FIG. 3 is a developed view of the sinker cam assembl FIG. 4 is a bottomview of the sinker cam assembly;

FIG. 5 is a detail sectional view taken along the line VV of FIG. 4;

FIG. 6 is a perspective view of a device for actuating the additionalcam for the sinkers;

FIG. 7 is a perspective view of a device for actuating the additionalcam for the needles;

FIG. 8 is a side e-levational view of a sinker used in the circularknitting machine embodying this invention;

FIG. 9 is a diagrammatic view of several sinkers and needles during aphase of the formation of the double welt of a stocking;

FIG. 10 is a schematic view on an enlarged scale, of the stitch patternof the first courses obtained during the operation illustrated on FIG.9;

FIG. 11 is a view similar to FIG. 9, but illustrating a phase in theformation of the double welt according to a modified method ofoperation;

FIG. 12 is a schematic view, on an enlarged scale, of the stitch patternof the first courses as obtained by the method of operation illustratedon FIG. 11;

FIG. 13 is a schematic developed view of the upper parts of severalneedles and of the corresponding sinkers which are situated in theregion of the knitting cam and the additional cam of the needle camassembly; and

FIG. 14 is a diagrammatic view showing the arrangement of the needles inthe needle cylinder and of the sinkers in the sinker supporting ring.

The drawings show only those parts of a conventional circular knittingmachine for the manufacture of hosiery which are absolutely necessaryfor understanding the invention. Naturally all other parts of theknitting machine, which are neither illustrated nor described, areconventional and can be constructed so as to operate in a mannerconsistent with the corresponding parts of existing circular knittingmachines. In order to simplify the specification and drawings, theinvention is disclosed herein as being embodied in a single-feedmachine, but it is to be understood that the invention may be similarlyapplied to machines having a plurality of feeds.

Referring to FIG. 1 in detail, it will be seen that the circularknitting machine there shown essentially comprises a cylinder 1 having asinker supporting ring 2 secured on its upper end portion. Latch typeneedles 3 are vertically movable in axial grooves formed in the outersurface of cylinder 1, and the needles are held in the related groovesby the turns of a surrounding helical spring 4.

Sinkers 5 are displaceable in radial grooves of the sinker supportingring 2 and are surrounded by a spring ring 6 which urges the sinkersradially inward. The cylinder 1 is secured on a tubular sleeve 7 whichis rotatable in the machine frame 8 and provided with an outer ring gear9 which meshes with a spur gear 10. Gear 10 is secured on a shaft 11journaled in the frame 8, and which is driven by a motor (not shown).Arranged coaxially around the lower part of sleeve 7 is a main controldrum 12 which is suitably turned and controls the entire cycle of theknitting machine in the usual manner.

A ring 13 is secured on the machine frame above the sinker supportingring 2 and carries the cam for controlling the sinkers 5. FIG. 1 showsalso a thread guide arm 14 which feeds the thread to a point in thevicinity of the upper edge of the needle cylinder where it can beengaged by the needles 3. Fixedly supported about the needle cylinder 1is the cam assembly 15 for controlling the needles 3.

The machine parts described above correspond to those generally providedin all known circular knitting machines for the production of stockingsand socks and the operation thereof is similarly well known.

Specially designed sinkers are used in the machine according to theinvention, and such sinkers may have, for example, the configurationshown on FIG. 8. Each sinker has a shortened cast-off ledge 17 and anadditional nose 18 under the regular nose 19. The two noses form abottom groove or notch 20 under the nose 18 and an upper groove 21between the noses 18 and 19. Each sinker 5 further has a stop 22 for thespring ring 6 to act against a butt 23 and a guide notch 24..

The major proportion of the sinkers inserted in the radial grooves ofthe sinker supporting ring 2 have a short butt 23a and only a smallnumber of the sinkers, which are all grouped together, have a long butt2317, as represented schematically on FIG. 14, where the sinker butts23a and 23b, which actually extend upwardly, are shown developed in ahorizontal plane. The reasons for these different lengths of the sinkerbutts will be explained more fully below.

FIG. 2 shows some of the most important cams of the assembly 15 forcontrolling the needles 3. The illustrated cams include the centralupper cam 26 and the withdrawing or knitting cam 27 which, in thepresent case, is positioned to act on all of the needles during theproduction of the entire stocking. An additional cam 29 is provided toeffect downward movement of selected needles when disposed in certainoperative positions, and a lifting cam 30m is operative to lift theneedles, so that the latter release their latches and are brought to alevel where they can engage the thread fed by the thread guide arm 14.Finally, a profiled guide ring 32m is provided to slidably support thebutts of the needles 3. This guide ring 32m is vertically positioned tolift the needles, after the downward movement or withdrawal, to avertical position where they neither release the needle latches nor arethe needles engageable with the thread fed by the thread guide arm 14.When the needle butts bear on the guide ring 32m, the hooks of theneedles are about at the level of-the upper part of the sinkers.

The arrow 33 on each of FIGS. 2, 3, 13 and 14 indicates the normaldirection of motion of the needles relative to the cams during thecontinuous rotation of the needle cylinder 1. In FIG. 2, those cams havebeen omitted which operate during the oscillating movement of the needlecylinder, as during the knitting of the heel and toe.

As can be seen from FIG. 2, the additional cam 29 provided in accordancewith this invention is displaced in the direction of the arrow 33, thatis, in the direction of normal rotation of cylinder 1, from the lowestpoint of the withdrawal or knitting cam 27 and the guide ring 32m has astep 31 between the lowest point of the cam 27 and the additional cam29. Thus, the needles lowered by the cam 27 are lifted to a certainextent by the step 31 before they can be lowered further by theadditional cam 29 assuming that the latter is operatively positioned toengage the butts of the needles in question.

Each needle has a butt-34, and these butts are of four differentlengths. The needles are arranged in the grooves formed in the outersurface of cylinder 1 so that relatively long and short needle butts arealternated whereby a certain selection of the needles is possible, aswill be explained below. In order to permit the engagement anddisengagement of the cams 29 and 30111 by radial movement thereof towardand away from the circumference of the needle cylinder, the needles in alimited zone or group are provided, in a known manner (FIG. 14) withlong butts 340 which are longer than the long butts 34a of the needlesin the rest of the needle set, and with short butt-s 34d which areshorter than the short butts 34b of the needles in the rest of theneedle set. It should be noted, however, over the entire circumferenceof the needle cylinder a needle with a relatively longer butt 34a or 340always alternates with a needle with a shorter butt 34b or SM.

Each of the cams 29 and 30m can be individually con- I to its highestpoint.

trolled to assume different positions, that is, different radialdistances from the outer surface of the needle cylinder. The cam 29 iscontrolled to take any one of five different positions: In a firstposition cam 29 is inactive for all needles; in a second position cam 29acts only on the needles with the longest butts 340; in a third position cam 29 acts on all needles with long butts, that is, both on thosewith long butts 34c and on those with long butts 34a; in the fourthposition cam 29 acts on the needles with the butts 34a, 34b, and 340;and finally in a fifth position it acts on all needles, including thosewith the shortest butts 34d. The cam 39m can only assume threepositions. in a first position it acts on all needles; in a secondposition it only acts on the needles with butts 34a, 34b and 34a; and,in a third position, it is inactive with respect to needles with shortbutts 34b and 34d and, therefore, only acts on the needles with longbutts 34a and 34b.

The cam 29 is not only displaceable radially toward and away from thecircumference of the needle cylinder, but it is also vertically movableto permit variations of the stitch width by means of this cam.

FIG. 7 shows schematically a suitable device for controlling the cam 29,and a similar device can be used for controlling the cam 30m. Thecontrol device for cam 29 is actuated by steps 35 and 36 on cam rings 37and 38 carried by the contnol drum 12. The ring 38 is contacted by thenose of a feeler lever 40 which is secured on a shaft 42 journaled inthe machine frame. The shaft 42 carries an arm 44 which is in contactwith a pin 46a on a slide 46 which has the cam 29 extending therefrom inthe direction radially toward cylinder 1. The cylindrical shell of camassembly 15 has a suitable opening (not shown) through which the cam 29can extend more or less into the path of the needle butts. A spring 45holds pin 46a in contact with arm 44 and consequently urges the nose ofthe lever 40 against cam ring 38.

When the nose of feeler lever 40 is in contact with the ring 38, asshown on FIG. 7, the cam 29 is in the position closest to thecircumference of the needle cylinder. However, when drum 12 is turned toengage the cam steps 36 with the nose of lever 40, cam 29 is displacedradially outward from the circumference of the needle-cylinder. Sincethe stepped cam 36 has four steps, this radially outward displacementcan move cam 29 to four different positions. In the first of thesedisplaced positions cam 29 is made inactive only for the needles withshort butts 34a; in the second displaced position cam 29 is madeinactive for all needles with short butts 34b and 34d but remains activefor the needles with long butts 34a and 340; in the third displacedposition cam 29 is made inactive for the needles with the ibutts 34b,34c and 34d; and, in the fourth position, caused by engagement of lever40 with the highest step of cam 36, earn 29 is inactive with respect toall needles.

The slide 46 is guided between two stationary, horizontal pins 56 and 57so that it can rock about a horizontal axis between the pins 56 and 57,in addition to being displaced longitudinally. Such rocking movement ofslide 46 is controlled by the cam ring 37 on drum 12.

In contact with the ring 37 is the nose of a feeler lever 39 which issecured on a shaft 41 journaled in the machine frame. Shaft 41 alsocarries an arm 43 which has an adjusting screw 50 extending through itsfree end portion. This screw is in contact with one arm of a bell-crank58 which is pivoted at 58a and has its other arm hearing from above onthe slide 46. The slide 46 is urged upwardly into contact with thebell-crank 58 by a spring 65.

When the nose of the lever 39 rides on the ring 37 of the drum 12 (asshown on FIG. 7), the cam 29 is lifted However, when the nose of lever39 is engaged by the cam 35 on ring 37, the cam 29 is displaceddownwardly to an extent dependent on the radial height of the cam 35 atthe point of its contact by lever 39.

7 Referring now to FIGS. 3 and 4, it will be seen that the sinker camring 13 has an annular, downwardly opening cam groove 47 receiving thebutts of the sinkers which are of different height, as mentioned above,a larger group or zone of sinkers being provided with shorter butts 23a,and a smaller group or zone of sinkers having taller butts 23b. Theannular groove 47 has a cam portion 48 for displacing all of the sinkersradially outward to a certain extent. Displaced circumferentially fromthe cam portion 48 in the direction of the arrow 33 is an additional cam49 which can be inserted from above into groove 47, and which is thenoperative to cause an outward movement of the sinkers that is greaterthan that caused by the cam portion 48. The division of the sinkers intoa group with short butts and a group with long butts is for the purposeof permitting the engagement and disengagement of the additional cam 49.

The additional cam 49 is secured on a stirrup 51 pivoted at 52 on themachine frame (FIGS. and 6). A spring 53 acts on stirrup 51 to urge thelatter in the direction for introducing the additional cam 49 from aboveinto a recess of the annular groove 47. The stirrup 51 bears on aprofiled ring 54 which is angularly displaceable on the sinker cam ring13. The ring 54 has, on its upper edge, a two-step cam 55. The firststep of cam 55 lifts the stirrup 51 and the cam 49 so that the latterbecomes inactive for the sinkers with short butts 23a, while the secondstep of cam 55 lifts the cam 49 to a position in which it is inactivefor all sinkers. When the stirrup 51 bears on the ring 54 under theaction of the spring 53, the additional cam 49 is active for allsinkers.

The displacement of the ring 54 along a circular path on the sinker camring 13 is effected by the control drum 12 which is provided, for thispurpose, with a two-step cam 59 (FIG. 6). The nose of a feeler lever 60contacts the drum at the level of cam 59. The lever 60 is secured on ashaft 61 carrying an arm 62 having a forked free end which engages a pin63 secured on the ring 54. A spring 64 acts on the arm 62 to urge thelatter in the direction for urging the nose of the feeler ever 60 incontact with the surface of the drum 12. When the feeler lever 60 bearson the drum, the additional cam 49 is fully extended into cam groove 47for engagement with the butts of all sinkers. When the nose of thefeeler lever 60 is on the first step of cam 59, the additional cam 49 isinactive for the sinkers with short butts 23a. When the second step ofthe cam 59 engages the nose of lever 60, the additional cam 49 iselevated to a position in which it is inactive for all sinkers. In FIG.5, the completely inactive position of the additional cam 49 isindicated by dot-dashed lines, while the cam 49 is shown on FIGS. 3 and4 in its active position for all sinkers.

A possible method of operation of the circular knitting machine for theproduction of the double welt of a stocking will now be described with areference to FIG. 9. In this view of the drawings, there is a schematicrepresentation of one of the sinkers 5 shown partly broken away, and ofseveral needles 31, 311, 3111, 31V, 3V, 3V1 and 3VII which cooperate toform the knitted fabric. The courses of the knitting are designated bythe capital letters A, B, B and C. The needles 3-I, 3-III, 3V and 3-VIIhave long butts 34a or 340 and the needles 3-II, 3IV and 3-VI have shortbutts 3412 or 34d.

For the production of the first course A at the start of the welt, thelifting cam 30m in the needle cam assembly is postioned so that it canact only on the long-butt needles 3-I, 3-III etc.

This setting is achieved as follows: At the end of the production of thepreceding stocking the lifting cam 30m is positioned so as to act on allneedles. Before the start of the production of the first course of thenew stocking, the lifting cam 30m is displaced radially outward from theneedle cylinder, at a time when the cam 30m is being passed by the zoneincluding needles with short butts 34b, s-uch displacement of the cam30m being to the postion Where is can no longer act on the needles withshort butts 34d. When the zone of the needles with short butts 34dpasses the cam 30m, the latter is moved further outward so that itbecomes also inactive for the needles with short butts 34b. Thus, thecam 30m is in a position in which it can act on only needles 3I, 3-IIIetc. with long butts 34a or 340.

Further, for the protection of the first course A, additional cam 29 isin its completely inactive position, or it can be engaged, as will bedescribed below, to widen the stitches, and the additional cam 49 in thesinker cam assembly is positioned to be inactive for all sinkers. Theformation of stitches with the long-butt needles is effected in theusual way on the cast-off ledge 17 of the sinkers and the first course Ais laid into the upper grooves 21 of the sinkers.

For the formation of the second course B, the lifting cam 30m is movedradially inward to the position Where it can act on all needles. Suchradially inward movement is effected in two steps as follows: When thezone of the needles with short butts 34d passes the cam 30m, the latteris moved radially inward toward the needle cylinder to lie just outsidethe butts 34d. When the needles with short butts 34b subsequently arriveat the position of the cam 30m, the latter can already act on theseneedles and can be then moved closer to the needle cylinder so that itcan thereafter also act on the needles with short butts 34d.

This type of two-step (or multiple step) engagement of a cam is known initself and, therefore, will not be described here in greater detail.

For the production of the second course B, the additional cam 29 isdisengaged, if it has been previously engaged for stitch widening, andit is made inactive or brought into a position in which is causes aminimum widening of the stiches. Further, the additional sinker cam 49remains disengaged and inactive for the production of course B. Theproduction of the start of the stocking is thus continued in knownmanner on the cast-off ledges 17 of the sinkers.

The production of the following course B is effected in the same manneras the production of the preceding course B on the cast-off ledges 17 ofthe sinkers. However, the additional cam 29 is moved to the positionwhere it can only act on the needles with long butts 34a and 340 and theadditional sinker cam 49 is displaced to the position where it is activeon all the sinkers. Such displacement of cam 49 is effected in twosteps. During the passage of the sinkers with short butts 23a cam 49 islowered so as to lie just above these butts, whereby the cam 49 canthereafter act on the butts 23b for displacing the related sinkersradially outward. While cam 49 engages butts 23b it is moved furtherdownward so as to be finally positioned for engaging the sinker butts23a. Thus, the course B is gradually moved down during its formationand, after the preceding course B has been deposited on the new stitchesby the withdrawal of the needles caused by the withdrawing or knittingcam 27, and by the further downward movement of needles with long butts34a and 340 which have been lowered by the additional cam 29, and whichtake along the corresponding stitches. Since the sinkers 5 are outwardlydisplaced at the same time by the additional cam 49 beyond thedisplacement effected by the regular sinker carn portion 48, the initialcourses drop down and the stitches of the course B formed by thelong-butt needles come to lie in the lower additional grooves 20 of thesinkers which are then immediately displaced radially inward by the camgroove 47 to retain the corresponding stitches of the course B in thelower grooves 20.

For the production of the following or connecting course C, the cams 30mand 29 remain in their existing positions, that is, with the lifting cam30m positioned to act on all needles and the cam 29 positioned to actonly on the needles with long butts 34a and 340, and the additionalsinker cam 49 is returned to its inoperative position. The course C isformed, like the preceding course, on the cast-off ledges 17 of thesinkers. In order to ensure that the preceding lowered course B is connected with the new stitches, the long-butt needles 3I, 3-III etc. arelowered by the additional cam 29 and also positioned to cause theformation of additional stitches. Consequently only those stitches ofthe course B formed with the long-butt needles 3-1, 3-III etc. are castoff on the corresponding stitches :of the course C and connect thecourses formed subsequently on the cast-ofl? ledges 17 of the sinkerswith thepreceding courses A and B which are held down by the lowergrooves 2410f the sinkers.

Following the production of hte course C, there is obtained the stitchpattern represented schematically on FIGS. 9 and 10.

It isdesirable to note at this point the following advantages achievedwith the invention:

During the production of the welt of a stocking, a particularly criticaland delicate moment is that of the transfer from the course B precedingthe connecting course to the connecting course C. This moment iscritical due to the high tensions to which the thread is subjected whenit is pulled'down by'the long-but-t needles acted on by the additionalcam 29 for the formation of the connecting stitches. Particularly longloops must be formed which obviously require an increased thread supply.

FIG. 13 shows very clearly how this increased thread supply is providedaccording to the invention without subjecting the thread to excessivetension. In FIG. 13, the withdrawingcam 27 is shown active for allneedles, while the additional cam 29 is shown acting only on thelong-butt needles. The needles are shown in the positions that theyassume at the end of the production of course B and at the start ofcourse C. In FIG. 13', it is assumed that the short-butt needle 3-II isthe last needle that forms the course B and that the long-butt needle3-III is the first needle to form the cource C, with the needles movingin the direction of the arrow 33. All needles, after they have beenlowered by the withdrawing cam 27, are lifted slightly by the step 31 onguide ring 32m. By reason of this slight lift of the needles, the loopstightened during the descent of the needles are left loose on the hooksof the needles, as can be seen clearly on FIG. 13. Since the short-buttneedles 3 -11, 3IV etc. are not acted upon by the additionalcam'2 9,these needles move in lifted position past the cam 29 and thus do nottightly hold the respective loops. It follows therefore that thelong-butt needles 3-III and 3'V acted upon by the cam 29 to pull theloops downwardly for establishing the connection find the necessarythread supply without excessive tensioning of the thread and the dangerof breakag'es, since these are loose loops, bothbefore and behind eachlong-butt needle, from which the thread supply. for the long loop can bedrawn.

In a modified method of production of the first courses of the weltaccording to the invention illustrated on FIGS. 11 and 12, and whichpermits a further reduction of the stress on the thread, the control ofthe cam 3m is selected so that only the long-butt needles are lifted bythe lifting cam 30m during the production of the third course B In thiscase, the short-butt needles do not cast off the previously formedstitches (of course B) and do not engage the thread for the formation ofcourse B The stitches held in low positons on the needle shafts of theshort-butt needles 3-II, 3lV, etc. belong in this case to course B, andthe stitches formed by the long butt needles are more easily cast off.In the modification of FIGS. 11 and 12, it is obviously essentially thatcourse B be completed, whereas the course B could be omitted in the caseillustrated by FIGS. 9 and 10.

The production of the courses follow the connecting course C and theconnecting of the welt to the body of the stocking can be effected inany known manner and are not part of the present invention, so that suchprocedures need not be described in detail herein.

' It will be seen from the above that the additional cam 29 in theneedle cam assembly 15 has the principal function, according to theinvention, of pulling down the initial courses formed before theproduction of the connecting course C. In order to perform thisfunction, it is necessarythat it cooperate with the additional cam 49 inthe sinker camassembly. Since the additional cam 29 does not function asan extension of the regular withdrawing cam 27, it can therefore effecta less pronounced downward displacement of the needles and be spacedfrom the regular withdrawing cam 27. The spacing between cams 27 and 29makes possible the arrangement of the step 31on the profiled guide ring32m to lift the needles again immediately after they have been loweredby the cam 27. Further, the additional cam 29 can function as a stitchwidening device to vary the stitch width in the different courses,particularly at the start of the production of the welt. It has beenfound in practice that particularly favorable results are obtained whenthe first course A is formed with wide stitches to impart elasticity tothe stocking, the second course is formed with narrower stitches, thecourse B with regular wide stitches and the connecting course C withwider stitches than the third course B to make sure that the long-buttneedles can cast off the stitches satisfactorily. In order to obtainthese variations of the stitch width, it is only necessary to arrangecams 35 of corresponding height at suitable points on the ring 37 of thecontrol drum 12. Although particular embodiments of the invention havebeen described in detail herein with reference to the accompanyingdrawings, it is to be understood that the invention is not limited tothose precise embodiments, and that various changes and modificationsmay be effected therein by One skilled in the art without departing fromthe scope or spirit-of the invention as defined in the appended claims.

What is claimed is: 1. In a circular knitting machine for the productionof hoisery with a double, outwardly folded-over welt and which comprisesa rotated cylinder carrying a set of latch type needles that are axiallymovable and alternately have long and short butts, radially movablesinkers located between the needles and each having a cast-off ledge andan additional radially opening groove below said ledge, a thread guidefor feeding thread to the successive needles, a needle lifting camengageable with said butts of the needles for raising the latter to alevel at which the needles can engage thread fed by the guide, a needlewithdrawing cam acting on the butts of the needles for effectingdownward movement of the latter after engagement of the needles with thethread, a sinker cam ring controlling the radial movements of thesinkers and having a portion effecting radially outward movement of thesuccessive sinkers upon said downward movement of the adjacent needlesby said withdrawing cam: the combination of an additional needle camspaced from the lowest part of said withdrawing cam in the direction ofrotation of said cylinder and selectively engageable with the needlebutts to effect downward movement of the needles beyond the lowermostposition to which the needles are moved by said withdrawing cam,

an additional sinker cam spaced from said portion of the sinker cam ringin the same direction, and by a corresponding distance as saidadditional needle cam with respect to said withdrawing cam, saidadditional sinker cam being selectively engageable with the sinkers toeffect radially outward movement of the latter beyond the movementthereof by said portion of the sinker cam ring,

means located between said withdrawing cam and said additional needlecam to effect slight lifting movement of the needles immediatelyfollowing the downward movement of the needles by said withdrawing cam,

control means for said additional needle cam positioning the latter toact only on the needles with long butts during a course which follows atleast one initial course and precedes a connecting course, and

control means for said additional sinker cam positioning the latter toact on all of the sinkers during said course which precedes theconnecting course.

2. A circular knitting machine as in claim 1; wherein said needlelifting cam is movable between positions where it selectively engagesonly the long-butt needles and the butts of all of the needles,respectively, and

further comprising control means for said needle lifting cam moving thelatter to said position where it engages only the long-butt needlesduring said course which precedes the connecting course.

3. A circular knitting machine as in claim 1;

wherein said butts of the needles are engageable from above with aprofiled guide ring, and said means to effect slight lifting movement ofthe needles is constituted by a step on said guide ring engageable withall of the butts.

4. A circular knitting machine as in claim 1;

wherein said additional needle cam is also movable vertically to adjustthe extent to which needles having their butts engaged by saidadditional needle cam are moved downwardly beyond said lowermostposition to which the needles are moved by said withdrawing cam, and

further comprising control means for the vertical movements of saidadditional needle cam.

5. A circular knitting machine as in claim 4;

further comprising a control drum for regulating the operating cycle ofthe knitting machine, and wherein said control means for the verticalmovements of the additional needle cam includes cams of differentheights spaced circumferentially on said drum, and actuating meansengageable by said cams of different heights in succession andcorrespondingly varying the vertical position of said additional needlecam.

6. A circular knitting machine as in claim 5;

wherein said cams of different heights are arranged on said control drumto move said additional needle cam to a lowermost position during theforming of the first initial course, to a highest position during theforming of a second initial course, to a central position during theforming of said course preceding the connecting course, and to a lowerposition, between said lowermost and central positions, during theforming of said connecting course.

7. A method of operating a circular knitting machine for the productionof hosiery with a double, outwardly folded-over welt, which machine isequipped with sinkers each having an additional groove opening radiallyinward below the normal cast-off ledge thereof, said method comprising,

(A) during the forming of a course which follows at least one initialcourse and precedes a connecting course, the steps of lifting at leastalternate needles sufficiently to cause the needles to engage thread fedthereto, slightly lifting each needle immediately following the normaldownward withdrawing movement thereof, thereafter downwardly displacingthe alternate needles to an extent beyond said normal downwardwithdrawing movement of the needles, and simultaneously effectingmomentary radially outward displacement of all sinkers to an extentbeyond the normal radially outward movement of the sinkers whichaccompanies said normal downward withdrawing movement of the needles sothat the stitches of each initial course and of said course precedingthe connecting course are retained in the additional grooves of thesinkers below the normal cast-off ledges; and (B) during the forming ofthe connecting course, the

steps of lifting each needle to engage thread fed thereto, slightlylifting each needle immediately following the normal downwardwithdrawing movement thereof, and thereafter downwardly displacing onlyalternate needles beyond the normal downward withdrawing movement of theneedles while retaining the sinkers in radially inward positions so thatsaid alternate needles which are downwardly displaced draw long loops ofthread from the normal cast-off ledges of the sinkers to the stitchesretained in said additional grooves with the thread for said long loopsbeing supplied from the loose loops of thread on the slightly liftedneedles between said alternate needles. 8. A method as in claim 7;further comprising varying the width of the stitches formed duringsuccessive courses by adjusting the extent of the downward displacementof the needles 7 following said slight lifting thereof so that a firstinitial course is formed with wide stitches, a second initial course isformed with narrower stitches, said course preceding the connectingcourse is formed with stitches of normal width and said connectingcourse is formed with still wider stitches to facilitate casting-off ofthe latter from the related needles.

References Cited by the Examiner UNITED STATES PATENTS 2,785,552 3/1957Larkin 66-41 2,948,130 8/1960 McDonough 66-41 3,108,459 10/1963 Coile66-57 X 3,116,620 1/1964 Hanel et a1 66-54 FOREIGN PATENTS 1,289,308 2/1962 France.

0 ROBERT R. MACKEY, Acting Primary Examiner.

MERVIN STEIN, Examiner.

P. C. FAW, W. C. REYNOLDS, Assistant Examiners.

1. IN A CIRCULAR KNITTING MACHINE FOR THE PRODUCTION OF HOISERY WITH ADOUBLE, OUTWARDLY FOLDED-OVER WELT AND WHICH COMPRISES A ROTATEDCYLINDER CARRYING A SET OF LATCH TYPE NEEDLES THAT ARE AXIALLY MOVABLEAND ALTERNATELY HAVE LONG AND SHORT BUTTS, RADIALLY MOVABLE SINKERSLOCATED BETWEEN THE NEEDLES AND EACH HAVING A CAST-OFF LEDGE AND ANADDITIONAL RADIALLY OPENING GROOVE BELOW SAID LEDGE, A THREAD GUIDE FORFEEDING THREAD TO THE SUCCESSIVE NEEDLES, A NEEDLE LIFTING CAMENGAGEABLE WITH SAID BUTTS OF THE NEEDLES FOR RAISING THE LATTER TO ALEVEL AT WHICH THE NEEDLES CAN ENGAGE THREAD FED BY THE GUIDE, A NEEDLEWITHDRAWING CAM ACTING ON THE BUTTS OF THE NEEDLES FOR EFFECTINGDOWNWARD MOVEMENT OF THE LATTER AFTER ENGAGEMENT OF THE NEEDLES WITH THETHREAD, A SINKER CAM RING CONTROLLING THE RADIAL MOVEMENTS OF THESINKERS AND HAVING A PORTION EFFECTING RADIALLY OUTWARD MOVEMENT OF THESUCCESSIVE SINKERS UPON SAID DOWNWARD MOVEMENT OF THE ADJACENT NEEDLESBY SAID WITHDRAWING CAM: THE COMBINATION OF AN ADDITIONAL NEEDLE CAMSPACED FROM THE LOWEST PART OF SAID WITHDRAWING CAM IN THE DIRECTION OFROTATION OF SAID CYLINDER AND SELECTIVELY ENGAGEABLE WITH THE NEEDLEBUTTS TO EFFECT DOWNWARD MOVEMENT OF THE NEEDLES BEYOND THE LOWERMOSTPOSITION TO WHICH THE NEEDLES ARE MOVED BY SAID WITHDRAWING CAM, ANADDITIONAL SINKER CAM SPACED FROM SAID PORTION OF THE SINKER CAM RING INTHE SAME DIRECTION, AND BY A CORRESPONDING DISTANCE AS SAID ADDITIONALNEEDLE CAM WITH RESPECT TO SAID WITHDRAWING CAM, SAID ADDITIONAL SINKERCAM BEING SELECTIVELY ENGAGEABLE WITH THE SINKERS TO EFFECT RADIALLYOUTWARD MOVEMENT OF THE LATTER BEYOND THE MOVEMENT THEREOF BY SAIDPORTION OF THE SINKER CAM RING,